Under NFPA 1, which boiling point describes a highly volatile liquid?

Under NFPA 1, which boiling point describes a highly volatile liquid?

• A. Boiling point above 68 degrees F
• B. Boiling point below 68 degrees F
• C. Boiling point exactly 68 degrees F
• D. Boiling point not a factor

Answer: (B)

Volatility is about how readily a liquid forms vapor at typical conditions. NFPA 1 uses a boiling-point threshold of 68°F (20°C) to classify liquids as highly volatile. If a liquid boils below that temperature, it will readily vaporize at room temperature, producing significant flammable vapor that can form ignitable mixtures and spread hazards more easily. That’s why a boiling point below 68°F is the defining trait of a highly volatile liquid. If the boiling point is above 68°F, the liquid won’t vaporize as readily at room temperature, so it’s less volatile in everyday conditions. A boiling point exactly at 68°F sits at the boundary and isn’t categorized as highly volatile under this rule. “Not a factor” isn’t correct because NFPA 1 specifically uses this boiling-point criterion to describe volatility.

Volatility is about how readily a liquid forms vapor at typical conditions. NFPA 1 uses a boiling-point threshold of 68°F (20°C) to classify liquids as highly volatile. If a liquid boils below that temperature, it will readily vaporize at room temperature, producing significant flammable vapor that can form ignitable mixtures and spread hazards more easily. That’s why a boiling point below 68°F is the defining trait of a highly volatile liquid.

If the boiling point is above 68°F, the liquid won’t vaporize as readily at room temperature, so it’s less volatile in everyday conditions. A boiling point exactly at 68°F sits at the boundary and isn’t categorized as highly volatile under this rule. “Not a factor” isn’t correct because NFPA 1 specifically uses this boiling-point criterion to describe volatility.